Compress PDF for email
Most mail providers reject attachments over 20 to 25 MB. Shrink your PDF so it goes through on the first try.
Compress PDF files without uploading them.
Make PDFs small enough for email, job portals and government forms. Free, no account, no watermark. Nothing is ever sent to a server.
Use the arrows to change the order.
How to use Compress PDF
- 1
Add your files
Drop your files into the box or select them. They are opened only in your browser.
- 2
Choose your settings
Adjust the options if needed. The defaults work well for most files.
- 3
Download the result
Your new file is ready in seconds. Save it with one click.
Use cases
Reduce PDF size for every situation
Make a PDF under 1 MB or 2 MB
Job portals, universities and government websites often set strict upload limits. Use the “Strong” level to get under them.
Shrink scanned documents
Scans from phones and office printers are huge because every page is a photo. They usually get 70 to 90% smaller.
Works on iPhone, Android, Mac and Windows
Nothing to install. Open the page in any modern browser and compress PDFs on your phone, tablet or computer.
The PDF engine inside Chrome. In your browser.
coralpdf uses PDFium, the open-source PDF engine built into Google Chrome, compiled to WebAssembly. It finds every photo and scan in your document, scales it down to the resolution you choose and stores it as an efficient JPEG. Text, fonts and vector graphics are left untouched and stay razor-sharp.
- Runs in a sandboxed worker, isolated from the page
- A fresh engine instance for every file
- No network requests while compressing
Frequently asked questions
Are my PDFs uploaded?
No. Compression runs entirely in your browser and your files are never sent to a server. You can verify this yourself: open your browser's developer tools, switch to the “Network” tab and compress a file. Nothing is sent.
Is it really free?
Yes. Completely free, without an account, without a watermark and without a daily limit.
How much smaller will my PDF get?
It depends on the content. Scanned documents and PDFs with many photos often shrink by 70 to 90%. Text-only PDFs are usually small already and shrink less. If a file is already optimal, you simply get your original back.
Will the quality suffer?
Text and vector graphics stay perfectly sharp. Only embedded images are converted to a lower resolution: about 72 dpi for “Strong”, 150 dpi for “Recommended” and 300 dpi for “Light”.
Why does the first run take a little longer?
The first time you compress a file, your browser downloads the compression engine once (about 2 MB). After that it is cached and starts instantly.
Can I compress password-protected PDFs?
No, encrypted PDFs cannot be compressed. Remove the password first, then try again.